1. Field of the Invention
The present invention relates to a substrate processing apparatus that subjects substrates to processing.
2. Description of the Background Art
Substrate processing apparatuses are used to subject various types of substrates such as semiconductor substrates, substrates for liquid crystal displays, plasma displays, optical disks, magnetic disks, and magneto-optical disks, photomasks, and other substrates to various types of processing.
Such a substrate processing apparatus generally subjects a single substrate to a plurality of different types of processing successively. A substrate processing apparatus as described in JP 2003-324139 A includes an indexer block, an anti-reflection film processing block, a resist film processing block, a development processing block, and an interface block. An exposure device is arranged adjacent to the interface block as an external device separate from the substrate processing apparatus.
In the above-mentioned substrate processing apparatus, a substrate carried thereinto from the indexer block is transported to the exposure device through the interface block after being subjected to anti-reflection film formation and resist film coating processing in the anti-reflection film processing block and the resist film processing block. After the resist film on the substrate is subjected to exposure processing in the exposure device, the substrate is transported to the development processing block through the interface block. After the resist film on the substrate is subjected to development processing to form a resist pattern thereon in the development processing block, the substrate is transported to the indexer block.
With recent increases in density and integration of devices, making finer resist patterns has become an important problem. Conventional exposure devices have generally performed exposure processing by reduction-projecting reticle patterns on substrates through projection lenses. In such conventional exposure devices, however, the line widths of exposure patterns are determined by the wavelengths of light sources of the exposure devices. Therefore, making finer resist patterns has had limitations.
Therefore, as projection exposure methods allowing for finer exposure patterns, a liquid immersion method is suggested (see, e.g., WO99/49504 pamphlet). In the projection exposure device according to the WO99/49504 pamphlet, an area between a projection optical system and a substrate is filled with a liquid, resulting in a shorter wavelength of exposure light on a top surface of the substrate. This allows for a finer exposure pattern.
In the projection exposure device according to the above-mentioned WO99/49504 pamphlet, however, exposure processing is performed with the substrate and the liquid brought into contact with each other. When a contaminant adheres to the substrate before the exposure processing, the contaminant is mixed into the liquid.
Although the substrate is subjected to various types of film formation processing before the exposure processing, a bevel portion of the substrate or its peripheral portion may, in some cases, be contaminated in the process of the film formation processing. When the substrate is subjected to the exposure processing in the state, a lens of the exposure device may be contaminated, resulting in a defective dimension and a defective shape of the exposure pattern.
With the bevel portion or the peripheral portion of the substrate contaminated even during the film formation processing of the substrate, films may not be normally formed on the substrate.